Oil separator and pressure regulating device for aircraft ice eliminating systems



Dec. 22, 1953 D. M. LAwRE/NCE 2,663,522

OIL SEPRTOR AND PRESSURE REGULATING DEVICE FOR AIRCRAFT ICE ELMINATINGSYSTEMS INVENTOR ATTORNEY v Dec. 22, 1953 D. M. LAWRENCE r 01E SEPARATORAND PRESSURE REGULATING DEVICE FOR AIRCRAFT ICE ELIMINATING SYSTEMSFiled March 1l, 1947 4 Sheets-Sheet 2 INVENTOR /'VHLD 777. LHZL/HENL'EBY S ATTORNE Dec. 22, 1953 D. M. LAWRENCE OIL SEPARATOR AND PRESSUREREGULATING DEVICE FOR AIRCRAFT ICE ELIMINATING SYSTEMS 4 Sheets-Sheet 3Filed March 1l, 1945' 27 ATMOSPHE RE IIB 2 y a! Rm M 8 OE E -8 9 m. n mm E E MH M .Il I l Vdn T N T 4 6 Il@ A l 6 W Y w d 0 o/ I \h\\\\\ H l,B/W nu /m- .Ob 7 N I l nu 6 l 4 l I I M 7 c I I 6 f l L 4 4 9 2 5 6 f4 59 6 I: 11i H .d HIHIHHHHHHHHHIIIIIIIIIII Dec. 22, 1953 D. M. LAWRENCE2,663,522

OIL SEPARATOR AND PRESSURE REGULATING DEVICE FOR AIRCRAFT ICE ELMINATINGSYSTEMS Filed March l1, 194'? 4 Sheets-Sheet 4 INVENTOR /VHL 177.HIL/RENFE ATTORNE Patented Dec. 22, 1953 N ATING'L SEY STEMS DonaldM.f.Lawrence,.-Wood Ridge, NI J., assigner, 150; lelldix h'fiati'lmvCorporation Teierboro... Nj; J'.; a corporation of `DelawareApplicatiumMarcli 11, 1941,@ Serial l\T.0;\7,-33,$260` 14.Clai1 s.(011244-134) The present invention-'relateszto innatableepe eliminatingsystems for-'aircraft and -torimy l 1 vef ments vinthe"'mechanismadeseribedand cla ed in' `my -copencling applicationSerial No. 5853er, ledi'March 31.1, 19,45, ncw-PatentzNo; znfll. More'particularly thefpresent fapplicationirelates toda novelvoperating."system,. oil=separatorA and air lter forn preventing oil',other'. liquidar dirt` from# entering-V the :inatable: elements of thesystem'. Such" elements are-zgeneraliycom? posed of rubberorlikeffmaterial therefZ-ore Will-deteriorate it particles of-oilar per;ed to enter'the elements fW-ith the inflatingfraji: from the-air pumpJAn'obj ect ofthe-invention :is :tofprovideavnoyeielectricallyfcontrol-leck'oihseparator andfair ter Y device,`particularly adapted forV usei with an electrically.' controlled.:system .such as; shown 4 in the concluding application Serial No..498;,2i3'-, 'ledAugust 11, 1943, by Donald M. Lawrence, David Gregg 4and Myron L.; Taylor;

'Another object of the invention` isto provide a novel solenoidOperated" separator and; filter device.

Another object of the inventionis to prov-ide anovelseparator and filterdeviceso arranged that 'the -devic'e may be: placed-.in an operativecondition, only at such times as: the-icefeliminat-` ing systemfis'inlan operating` condition, so-as to.' increase. the lifeof. the. ltermaterial and reduce the size of the device.

Another 'object of i the? invention isto f provide in afcompact.assemblage a noveloilseparator anda-ir filter.

Another object of the--inventionv-is to provide a novel mechanism whichcombines theffunctionswof controlling an-dzlterin'g therairf pressuresupply 'forf inatahle icef: elimin ai-,ingv units'.

Another objectv ofthe invention is toproy-ide afnovel mechanismnwherebytheeairpressureto f inflatable ice eliminating units. may be auto,`matically regulated e accordingV to the-- momentary demands ofy thesystem; the-mechanism-prov-id-` 'ing novel means for discharging.;overboard; all pressure-air in excess of themomentary*requirement.

Another objectof the inventiony is. to provide ai mechanism embodying anovelimprov-ediva-lve structure over that ofthe disclosure of my' cc,-pending4v application Ser-iai No.- 585,941- nled Marchv 31, 1945,particularly in the simplifica-f tion of the twomain control valves andpressure release valve shownv in the latter: application; which have*`been simplified in; thepresent.v an@ plication.. into a single' controland regulating y valve Which eiectsl the: functions performeelubythel-three". aforenotedi valves` and inadditions performs' a, furtherfunctionA of. regulatingv the. air pressureJ to the inflatable ioefeliminating boots Aaccording to the momentary demands of the system.and. dischar5; es.overbC uzdall1 pressurefaifr inexcessofthemomentarydem-and,\ is based. Aupon @predetermined ,diigerential abat.the. boot .line pressure.. and- .atmospheric pressure as measured byanovel controla-diaphragm,.servo valve/means. A'

Another,- objlect of; i. the: invention Vis to; .spaargrangethe-.novel`-servo -valye anmmainvalyeas to effect stabil-ityoffcontrol. "Y 'yAnother object of.the inventioniispto .provide aT novel mechanism:whereby. only;M that por `"on of the airpressure@supply/.Whichrseaetually e1 quiredbymetinnatapiannits.isffinereqg, the tzr` allowingcthe utmost economy,andnemcieylv .regard4 to-.lter elementmsagei Another object `:of ,tlie;invention l:ist to .gravide a combination centrifugal oil separator;andgair filter of.- great 'efiiciency comparison Ll,',o,g.- ts, vSiaeand of Suchv Simplicity in weer tion... .assi to adapt itfor-manufaeturefanfiestaliaiien ation costL These` and4 cther'-.Qbjectsff and featuresfoi'L the inventionV areapointed out: inthe.rollout-1n dee scription in terms of the embodiment th which. isz Sheenin the: aorripanyirie; dra Il. iS t0.. tbe unilerswd; hQNYever, .that1tl1eed in gs are fcntl-1e ,#.purDQSV-:oi illustr are Ynot@designed as .aide Jntion.' theV` invention, reflffefief.y beine; hee pended claims forthis purpose.

In the;v draw-ings:l

Figure. l is? a1. fragmental'y'pliillr YQVWOL an aircraft; Showing;ldaerammaticellyf 11i in whichAv thermal-:mechanismiexceeeate the'.4inflatable-.V iceeliminatillg; System` Figure 2 is a schematic diagramof, the-:Imtech: anismg illustrating;theareeulatineraireimnaniinoperative relation;V

Figure 3f isfaV schematicdiagram ofA theymegnr anism: of; Figure 2;illustrating: the rgnlating valve'.- in 't an operativer relation.

Figure if is f anz enlargedi fragmentary@ seetional view illustrating;-th-e; operating` parte of.: thm-rege ulating' valve; me.charliemL.l

Referring; to; the drawing; orf Eieuref-l, is shown an aircraftindicated by the numeriil having anengine kandiinfiatabiezbcotef Quiltedalong. theleading-.edges of the piariecase; ,shew-1i', forexample;int-.tlie3 copending applientoin .Se 'al No.:v49,8;248i1edrAugust 11.129513, by Bona Lawrence. David'. Gregg; Iand`Myron. La. TaylQli. now Patent No. 2,515,5,1Qi-- The. engine 2isarrangediso aszto drireaniaircraft propellerL 5;.. Ani-ainpump:6is.also iriyen by the engine-.2; and. haszproriided'; a; suctioneen: duit-.1 leading. to'. thefmainsuctionrlinei' through suitablevrelief: `anclzvcheclr;v valves;vv as shownt Anf air: pressure; line 9i.leads; fromzthee'pump; 1 to the inlet ofrarr oilsepaiiator andaairfiter. ina dicated generaily by thernumeral lilla Bhe-:air

passes through the device I9 and during operation of the ice eliminatingsystem into the outlet conduit I2. During the passage of the air throughthe device ID, any particles of oil which may enter the air from thepump I9 or other source, is separated and the air is filtered from dirtand other extraneous matter. The air low thus processed, is conductedthrough the conduit I2 to the main air pump line l5.

The main suction and air pressure lines 9 and I lead to suitable airdistributor valves I8 which are electrically controlled by a timerindicated generally by the numeral so as to operate the inflatable bootelements 3. A plurality of such Adistributor valves are preferablyprovided of a type such as shown in the aforenoted copendingapplication. The timer 20 may be of the type 'shown in the lattercopending application or may be of a type such as shown in the copendingapplication Serial No. 498,250, led August 1l, 1943, by Myron L. Taylor,William B. Pond and Herbert A. Eayrs, now Patent No. 2,444,208. Theoperation of the timer is described in detail in the aforenotedcopending applications.

A manually operable switch is arranged to controlthe operation of thetimer, as will be readily apparent, through electrical conductors 26 andA2l leading from a source of electrical energy 28 while operation of theoil separator and air filter I0 is controlled simultaneously throughelectrical conductors 29 and 30.

` Thus by closing the switch 25 the timer 20 and the device I0 aresimultaneously placed in operation'by the closing of the circuits 26-21and 29-30 Awhich control the same. Switch 25 is open, the device ID isarranged so as to direct the air flow from the conduit I2 toran-overboard dump 3l as will be explained hereinafter.

The device I0, or regulating-unloading valve and oil separator,comprises a control head 40, shown schematically in Figures 2 and 3, andcontaining a pressure regulating and unloading valve 4I and a solenoidoperated servo valve mechanism 42.

The control head 40 has formed as a part thereof a plate 43 which formsthe cover for a casing 44 of an oil separator. The casing 44 has anupper annular end l45 suitably engaged in an annular grooved ange 46formed in the end plate r 43 as shown in Figure 4. Y Y

An opposite bottom portion of the casing 44 is formed by the inwardlyand downwardly extending sides 41 as shown in Figures 2 and 3. -Thecover plate 43 is secured in position by a tubular member 48. One end.of the tubular member 48 is screw threaded at 49 into a boss 50 on thebottom of the cover plate 43. The opposite end of the tubular member 48is screw threaded at 5I into the bottom portion 41 of the casing 44. Y f

The tubular member 48 has a passage 52 and ports 53 opening into thepassage 52 for permitting the drainage of oil from the interior of thecasing 44. VA suitable conduit 54 is connected 4to the end of thetubular member 48 for the drainage of oil therefrom.

' Extending from the top plate 43 isa second casing having its upperannular end 6I suitably engaged in an annular grooved iange 62 formed inthe end plate 43. The casing 69 is positioned within and in spacedrelation to the casing 44 and has suitably apertured uppergand lower endplates 63 and B4, respectively.

5 There is disposed within the casing60 a filter However, when i pack 65formed of a suitable material such as cellulose cotton material arrangedto absorb oil vapor. There may also be positioned in the casing 60 atthe upper end of the cellulose cotton material, a suitable layer ofactivated carbon or some other type of vapor absorbing material. Thereis thus provided in the casing 35 a lter pack 65 which may be held inposition by the top plate 63. The top plate 63 is fastened in positionby suitable means.

As shown in Figures 2 and 3, the inner casing 69 and bottom plate 64 arepositioned in spaced relation to the inner surface of the outer casing44 so as to define a passage between the inner and outer casingsindicated by the numeral 65. The tubular member 48, moreover, ispositioned in concentric relation to the inner and outer casings 44 and35. Between the perforated top plate 63 and cover plate 43 is provided acored chamber 61 which, as shown schematically in Figures 2 and 3, opensthrough a port 5S in the plate 43 into a cored outlet passage 99 formedin the control head 45. There is screw threadedly engaged in the outletpassage 69 one end of the pressure conduit I2, shown in Figure l.

As shown schematically in Figures 2 and 3, the control head 49 has fourports, the air pressure outlet port 69, an air pressure inlet port 1I),an air discharge port 1| and a suction port 12.

A mounting bracket 15, which is bolted to the control head 40 as shownin Figures 1 and 4, has an arm l which extends down alongside the casing44 of the oil separator and provides means for conveniently mounting thedevice I0.

As shown schematically in Figures 2 and 3, the control head 49 has anair inlet passage 19 in which there is engaged one end of the pressureconduit 9 leading from the air pump 6. The passage 19 opens into achamber 80. The discharge passage 1I opens from the chamber 39 into thedischarge conduit 3I while an oppositely disposed passage 8I opens fromchamber 89 into a chamber 32 formed in the control head 49. The chamberis separated from the chamber 82, as best shown in Figure 4, by a plate84 suitably fastened in position.

As shown in Figure 3, the chamber 3l opens through a cored passage 85into an opening 81 formed in the top plate 43 and leading into thepassage 56 formed between the inner and outer casings 44 and 65.

Positioned in the passage 66 is an annular ring 99 having formed thereina series of radialY varies, one of which is indicated in Figure 4 bynumeral 9|. The vanes 9i project inwardly through slots formed in thering Stand are so arranged as to give to the incoming air flow acentrifugal spin for a purpose which will be described hereinafter.

Controlling the opening of the passages 1I and BI into chamber 89 is thenovel pressure regulating and control valve 4S. As best shown in Figure4, the valve l4I comprises a frusto-conical portion and a resilient flapportion 95 afiixcd to one end of a valve stem 91 by a nut 98. Thefrusto-conical portion 95 extends into the passage 1I and regulates theair discharge as will be explained hereinafter, while flap portion 99cooperates with the open end of the passage 8I so as to control thepassage of air pressure from the chamber 89 to the chamber 92.

The stem 91 is slidably mounted in the passage 8| by a bracket 99affixed to the plate 84 by rivets IDI). The stem 91 extends through thepassage 8| into the chamber 82. K l

The inner end of the stemfStzis-.fastened:by a Iit-|-|2tora flexiblediaphragml member |.02which extends-.across the chamber 82l and issuitably mounted.-.therein. As-.shownin Figures -2 and 3 the. diaphragm-I'iz' thus provides inthe control head-Ianothcn chamber indicatedk bythe nunieral-|||31i Positioned =inthe cham-berl-IGSista coil springIllfhwhichbias'es the-diaphragm- I'EZfas viewed inHFigures--ZyS and 4.in a 4direction toward the left so.as to cause theregulatin'g valveportion 951150 movein a direction to close` the opening 1I and theapvalveportion 196 l -in- .a like direction so: as; to4 openthe passage 8I! to. the. air pressure in chamber As`- shown `in :Figures'B and 3, ableed passage Iileadsiromfthe chamber. m3 to. a passage |06 formed inftheY servo: .valvemechanism 42; During'-in'operation or vthe servo-valvemechanism 42,.

the passage |05 is 4connected through passage f I|I6,-.aslshown in.Figure 2, to the suction port 12 connectedv toa suction conduit |08 andthereby to1suction line 8. The sub-atmospheric pressureinithesuctionline .8 is thus applied to thediaphragm v'II12 rat the.chamber |93 through the u bleed Isoas' to raugment theV air pressureapplied tothe' valve portiona95 at the chamber 80 and counteract. the.force exerted by the spring IM'and normally'vhold the flap valve'portion96 so as tov close the' passage-8I- tothe' chamber 80.

The servowvalve mechanism d2, as shown in Figures-2 and 3,includes asolenoid or electromagnet', HIV-which vis :electrically connectedthrough connectorplug- IIIindicated in Figures 1 anduifwith the circuit29 and 30 previously describedwith reference tok Figure 1.

The solenoid III) -controls the movement of van armature I I2fastenedr'to one end otv a valve stem IIS slidablymountedin Ath'evalvepassage IfGl-- A spring IIJ, is mounted in the passageYIIJIfatftheopposite end of the Valve stem II3. Thestemi I3I is -biasedunder force of the spring |I41.i'n a direction opposing the action ofthe solenoid IIII.;-

The valve stem: I I3 has valve members I I5 and lI IBf."AsshowninFgures- -2 and 3 the valve portion'L-YI I5` opens the suctionport 12 to valve passagez-Iu'pon deenergization of the solenoid III)anda closes port 121 to valve passage '|06' upon energizationof `thesolenoid I IIL Upondeenergization of the solenoid IIO,.the l valveportion I IIS-closes the opening of a port I I 1 to thelvalve.passageV|06 and opens the port II1 to2 the Avalve vpassage I 05 uponenergization of the solenoid lI I0. The port II'I leads through arestricted-passage IIB to a chamber II9 which is fini-'turn 'connectedthroughA a cored passage |20 lformed in the control head to the -airoutlet pressurefpass'age 69, asl shown schematically in Figures2 and 3.v

It'will be seen' then that duringdeenergization o'ffthesolenoid lI II)the chamber |03 is connected through passagel, I6 and 12- to a source ofsuction. However, upon energization of the solenoid-I I'Ilthe chamber|03 is connected to a source ofair pressurefthrough passage |05,'|Il6and I|1 so as Ato augment the biasing force applied by -spriirigi/Id'fto`the diaphragm and cause the liiap valve portion- 96 to open passage 8|to chamber 80" and cause valve portion @5to tend to close the-dischargeconduit 1| to the chamber as indica-ted in-F-igures 3 and 4. Due-to themechainismf herein provided, however, the -valve `portion-S5 4is-regulated lso -as r to maintain the outlet pressurein the -passageIillatfa predetermined 6'. diierential'. irrvexc'esss vof .thefprevailirrgratmo's-i pherieipressure- Thewlatter yregulating. .actionis reffected by. -a second regulatonvalve. mechanism .comprisingaval-ve: stem I2 I slidably :mounted in .a .chamber I2.2t and aiixedl at.oneaend tof' va .diaphragmvl |23 which separates chamber =I-I 9 from.another cham@ bei` |241 open vtouatmospheric ypressure through a port125.11 A springA |26" biasesf. the :diaphragm A|.2-2fitowardfthechamber'fzl I9 Aand may. be ex. teriorlyf.ad-dusted *through anadjustment/.bolt 12.12;:

At the opposite end of the valve .-stem I2Ir .there isprovided=v-aneedle valve |28' which controls a valverportl 29.l opening betweenchamber.' I'222fand a chamber-430.1!v

A passage` I 3 I1 f-connectschamber lI 30tothe'suctionfports12; :whileapassage |32 connects 'cham-- ber |22 to the passage II1. Thus the needlevalve. I 282 isi regulated-.byv they diaphragm I 23vr so as` to .causethefpressurenapplied 'to .diaphragm |0'2Itoieffectthe regulatorvalve-r4|1so as to-maintainurthelair,pressure-fat the outletpassage 69ata :predetermined-diierential in excess of th at` mospheric-lpressureactingfonv the diaphragm' yI 232 Itwill-bezseen from lthe foregoingarrangementy that during the regulating operationv Aof thevalve. 4I, theportionserves'to regulate the .air outflow .from chamberI 80k throughdisi chargezconduit 11|", 'while the flap 4valve'portion 96' cooperatestherewith inY regulating the opening 8h and the air lo'w from thechamber-801:0 the chamber'82.

Moreover, the arrangement of the diaphragm |02 so -as tube-subject tothepressure `inf'the chamber 82 provides a convenientmeans for effectingstabilityocontroL Thus sudden changes inithe .-air inlet pressure willbe reflected by move'- ment ofth'ediaphragm IDZfand-valve 4I`to cor--rect for. such change.- Thus'the diaphragm |02 ineffect anticipates@change in' the pressure at the air outlet conduit 69 due to the change;`in thezairninlet pressure -so as toprovide stability 012 controlsOperation.

When the solenoid .I Iis deenergized'control valve ||5 is held in aposition-whereby suction is applied. through .the'passages 12,156and-|05 leadiri'gpintov the, .chamber I3f.f The-suctionis sucient;torforce thediaphragm `Il12lto com-A pressfthe spring |04. Inthisapostion the-diaphragm 1 I||:1'ioldszr the c valveH mechanism 4I soas.y tofclose-passage 8| to the-chamber 80 and allow ,theair underpressure flowing through the inlet port 10 to pass .directly outthroughl the over2board exhausty conduit 3| as shown `in Figure Whenthesolenoid` .I I IJ is energized, the control valveiofemembers. I I5 and II6 move to the positionushowni in Figure 3 wherebyv the directy suc--tlonfzpassage .'12 is closed off' and passage I I1l is openedaall'owing'the -diaphragm'- under air pres-f sure to expands .forcing thediaphragm^| 02. 1:0 'movestheivalveu mechanismd int-o Kthe operatingposition of Figure 3.

In this .position some of the air under pressure will ibe admittedthrough v-thepassage 8 I* and 'as showneinvFigure 3 'will pass throughthe cored passage. 86' toxthe inlet of the oil separator 81. The...latter operation permits the air yentering the .passage A1|J`underypressure of the pumpf to iioiw. .through the chamber 80, passagel,chamber :B2-land .the cored passage A8Iinto passagejj of the oilseparator. In the latter passageb",

the radial vanes 9| give the air a centrifugal spin tending to separatethe particles of oil from the air. The thus separated oil particles tendto drip down the inner sidey of the casing 44 and collect in therecessed bottom 47. The oil thus collected is discharged through theport 53 and passage 52 of the tubular member 48.

The air flow, moreover, passes downward and up through the perforatedbottom 64 of Vthe casing 6|l` and into the lter pack 55 where the oilvapors are absorbed. The air then continues to flow upward and throughthe perforated top plate 63 into chamber 67.

From chamber 6l the air passes through passages Si? and 69 into theoutlet conduit I2. The air flows through outlet conduit I2 to the mainpressure conduit I5 and through distributor valves IS to the inflatableice eliminator groups 3.

Simultaneously the control components of the unit I0 will begin toregulate the air outlet pressure according to the setting of theadjustment screw |27 which determines the regulating point of controldiaphragm |26. The internal connection indicated by the dash line inFigure 3 references the air pressure at the outlet 69 to that in thepressure diiferential chamber I I9.

Thus, the control diaphragm |23 will be sensitive to deviations from thedesired pressure at the outlet 69. If this outlet air pressure isexcessive, the control diaphragm |23 will be forced upward overcomingthe force of its spring |25 and the atmospheric pressure applied throughport |25.

In this position the control diaphragm |23 operates the needle valve |28so as to open the passage |29 and thereby the passage |I to suctionlapplied through passage |32, chamber |22, passage |29, chamber I3,passage |3I and passage 'I2. The suction is in turn applied from passageIl through restricted port I I8 to chamber I I9.

Some of the suction will also be applied back through the passage |I1and |05 leading into the chamber |03 and will aid in actuating the s;

diaphragm |332 to partly open the discharge port 'H thereby reducing theamount of air pressure to the oil separator.

' If the outlet air pressure at the passage 69 is insuicient the controldaphragm I 23 will progressively close the needle valve opening |29allowing the` diaphragm |02 to expand until the valve portion 95entirely closes the passage to the overboard exhaust 7| and all theavailable air pressure suply will be applied through the a oil separatorto the outlet passage 69.

It is to be noted that only the air pressure ow which passes to theinflatable ice eliminator boots is filtered, and thus effecting aneconomical usage of the lter material. Also, before reaching the filtermaterial 65, the air pressure flow passes down the relatively coolersides of the casing 44, so that much of the oil vapors Will be condensedon the side of the casing 44. An .outlet plug 54 is provided to permitdrainage of this condensed oil.

Although only one embodiment of the invenf tion has been illustrated anddescribed, various changes in the form and relative arrangements of theparts, which will now appear to those skilled in the art, may be madewithout departing from the scope of the invention. Reference is,therefore, to be had to the appended claims yfor a definition of thelimits of the invention.

What is claimed is:

l. A device of the character described comprising, in combination, acasing having air inletV and air outlet means for air undersuperatmospheric pressure, means carried by said casing for separatingoil from oil ladened air, means operatively connecting said separatingmeans between the inlet and outlet means, an air discharge means leadingfrom said air inlet means, a valve member carried by said casing tocontrol said air discharge and air outlet means and alternately operableto open an-d close the connecting means between said air inlet means andsaid separating means, and regulating means responsive to thesuperatmospheric pressure to operate said valve member so as to maintaina predetermined air pressure condition at said air outlet means uponsaid valve member opening said connecting means between said air inletmeans and said separating means.

2. A device of the character described comprising, in combination, acasing having air inlet and air outlet means for air undersuperatmospneric pressure, means carried by said casing for separatingoil from oil ladened air, means operatively connecting said separatingmeans between said inlet and outlet means, an air discharge meansopening from said air inlet means, a valve controlling said airdischarge means, motor means for operating the valve, and regulatingmeans responsive to the superatmospheric pressure at the air outletmeans ior regulating the operating motor means for said valve andthereby the opening of said air discharge means from said air inletmeans to maintain a predetermined air pressure condition at said airoutlet means.

3. For use in an ice eliminating system for aircraft having a pluralityof inflatable boots formed of a rubber-like material and mounted onairfoil surfaces of said aircraft, and a pump for providing a source ofsuperatmospheric air pressure for inating said boots; the combinationcomprising means for removing oil from oil ladened air, and said oilremoving means including an air inlet conduit and an air outlet conduitadapted to connect said oil removing means between said pump and saidboots, an air discharge conduit leading to atmosphere from said inletconduit, a valve member for regulating said discharge conduit andVthereby the air inlet pressure to said oil removing means, a thirdconduit connecting the inlet conduit to said oil removing means,operating means for said valve member, operator-operative control meansfor said operating means to affect said valve member so as toalternately open and close the third conduit, and control meansresponsive to the superatmospheric pressure and eective upon the openingof the third conduit to control said operating means so as to regulatesaid valve member and thereby said discharge conduit to maintain apredetermined boot inflating pressure condition in said outlet conduit.

4. For use in an ice eliminating system for aircraft having a pluralityof inflatable boots formed of a rubber-like material and mounted onairfoil surfaces of said aircraft, and a pump for providing a source ofsuperatmospheric air pressure for inflating said boots; the combinationcomprising means for removing oil from oil ladened air, and said oilremoving means including an air inlet conduit and an air outlet conduitadapted to connect said oil removing means between said pump and saidboots, an air accesses said electromagnetic'- means'in one :se'nse'tolcon- 'trolfsaid' operating meansl so vas to'regulate said valve memberand' thereby said discharge conduit toI maintain a predetermined bootinflating pressure condition in :said outlet conduitduring'` theoperation of the ice eliminating system.

5:For use-in-an ice'elirninating systemv vfor aircraft having avpluralityviof'inflatable boots formed of a rubber-like'material andmounted on vairfoil surfaces of said aircraft, and a' pumpfor-"providing a source Aof superatmosphericy air pressure forfinfiatingsaidl boots; 'the combination comprising means for removing `oill from;oil ladened; airand said oil removing means including an air inlet.conduit and an air outlet conduit adapted `to connect said oil removingmeans between said-pump and said boots, an air dischargev conduitleadingto atmosphere from thev air inlet-conduiuand an air release valvefor-regulating isaidair discharge conduit and thereby theIsuperatmospheric air pressure -applied through said oil` removing meansto said 'air'outlet conduit; and diiiere'nti'al` pressureresponsivemeans sensitive tothe atmospheric pressure and thesuperatmospheric pressure for operating said-valveso as to maintainlthefair Vpressureapplied to said boots through said outlet conduit ata^ pressure in excess ofprevailing atmosphericpressure by apredetermined-.value k6. 'For -use' in an'xice eliminating, system .for

aircraft having a plurality of inflatable boots and a source ofsuperatmosphericfluid pressure for inlating 'said boots;A lthecombination. comprising a lcasingv having a uuid discharge. openingtoratmosphere and includinga.'fluid`..inlet conduit andy a' fluid outletconduit for,` iuidunder super'atmospheric pressure, a movable valvemember alternately operable to close saidfluid outlet'conduit tol saidfluid inlet conduit oropen said: flu-id outlet. 'conduit to saidluid..inletu vconduit, and regulate said fluid "discharge, conduit,

means for-removing oil fromqthejiiuidinsaid outlet conduit, and'differential pressure responsive means sensitive to atmospheric pressureand the1 fluidpressure in said outlet conduit for operating .saidU valvemember so as to regulate said uid'discharge opening to maintain the uidpressure in--sa'id outlet conduit at 'a pressure in excess :ofprevailing atmospheric pressure by' a predetermined.v value, and said.`diiferential pressure responsive. means being effective onlyv upon said,va-Ive'. member opening said outlet con-duit to lsaid inlet conduit.

7.: A'vcontrolmdevice comprising, in combination, ,an inlet conduit forairl under super-atmosphericfpressura. an air discharge conduit openingiromf said. .air inlet conduit to atmosphere, an outlet conduit for saidair pressure opening from said inlet conduit, a main valve member foralternately opening and closing the opening of said outlet conduit fromsaid inlet conduit.

said main valve member also effective for "regulatingM'the` opening-ofsaid-*discharge conduit `from said air inlet y'conduit upon thevopening-of said outlet-conduit, motor means for positioning saidmainvalve member -so` as t'omaintain" a predeterminedpressure'conditionat said air outl'et'conduit; said motormeans-including a pressure sensitive member affected at one` side by'the-pressure of thel air in-'said outlet conduit,operatoroperativeservo valve means for applyings'electivelysuperatmospheric and sub-atmospheric pressures tothe opposite-side ofsaid 'pressure 'sensitive-member for controlling'the-position of *said*mainvalve member relative f to the openingof -said outlet conduit fromsaid inlet conduit; aregulating'valve for controlling the application ofysaid Superatmospheric i and subatmosphericpressures tothe :oppositeside of said pressure-'sensitive "member .upon the 'openingof saidoutlet "conduit'from said` inlet conduit-,by said main' valve member;'and *differential` pres sure'responsive means forcontrollingsaid-'regulating valve 'so as 'to-maintain a predetermined differential'betweenthe superatmosph'erim-pressure vatsaid `air outlet conduit andthe prevail-'- ing'atmospheric pressure.

8.v A device for removing oil from oil ladened air; comprising, `incombination, an outercasing, an inner casing' mounted within said outercasing and positionedin spaced relation thereto-'so asJto deiine. adownwardly extending air lpassage betweensaid casingsyan inlet conduitfora-ir under superatmosphericpressure, 'said air' inlet conduit havinga first valve opening connecting said `air inlet conduit-'to saidfirst-mentionedV airp-assage, an air4 outlet conduit' provided attheupperiend `of said inner Acasing;"means `carriedby at' *least* one'osaid' .casings for removingfY oil vaporsn froml Sai'd'oiVladened air'in passing Ifrom -saidair inlet conduit lrthrough' saidcasings tosaidairoutletconduit;` said air inlet 'conduit having a second valve openingtoratmosphere in alignment' withmsaid 'first valve opening, a-I lsinglevalvermemberpositioned-between said rst and second' valve openings insaid rair `inlet conduit, said'valve member feie'ctive foralternatelyopening and closing vthe rst `valve opening connectingsaidairA inlet conduit to Asaidfirst"mentioned ainpassageY ardiaphragm forcontrolling =the position lof said valve member; said'V diaphragm v'alsoeffective forpositioningsa'idv valve`member 'so-as to *regulate-'the'second valve opening to atmosphereto maintain the airl pressurein theoutlet-conduit at a vpredetermined value,r and differential;` pressure-responsive means to regullate said diaphragm upon said first valveopening connecting-said air inlet'iconduit to-lsaidfiijirstmentionedpassage lvbeing' opened f by said valve member;v vsaidla'stmentioned means being differentially 'affected' by' -prevailingatmospheric pressure and 'thesuperatmospheric pressure at ksaidair-'outlet conduit.

9:-l Ar` device Vfor removing oil from oil 'ladene'd air, comprising,-incombinationgan. outer casing, an'inner casing mounted within saidouter 'casi-ngand positioned in spaced relation theretoiso asttf-definaai downwardly extending` air passage between said casingsf aninletcond-uit for-'air under--superatmospheric pressure; means -connecting-rsaid: airinlet lconduit 4to lsaid firstmen- Y tioned airv passage, fairffilter means fcarriedfb'y said. inner casing? forrre'movingf oilv vaporsfrom said oil ladened air in passing' through 'fsa-id inner casing tosaid air outlet conduit, an air discharge conduit opening from said airinlet conduit, a single valve member for alternately opening and closingthe connecting means from said air inlet conduit to said air passage,said valve member effective for regulating said air discharge conduitupon the opening of said connecting means, a diaphragm operablyconnected `to said valve member, said diaphragm afected at -one side bythe pressure of the air in said last mentioned connecting means, a valvemechanism for applying selectively superatmospheric and sub-atmosphericpressures to the opposite side ofsaid diaphragm, anothervalve forregulating the superatmospheric pressure applied to said diaphragm, anda second diaphragm for positioning said other valve in accordance witha'predetermined differential between the superatmospheric pressure atsaid air outlet conduit andthe prevailing atmospheric pressure.

10. A device of the character described comprising, in combination, acasing having air inlet and air outlet means, means carried by saidcasing for separating oil from oil ladened air and connected betweensaid air inlet and air outlet means, an air discharge conduit connectedto ysaid air inlet means, an air pressure operated main valve, pressureresponsive means for regulating said main valve and thereby theconnection of said air inlet means to said discharge conduit inresponsive to the air pressure being applied at said air outlet means,and operatoroperative valve means carried by said casing and alternatelyoperable for affecting said main valve so as to open and close theconnection of said air inlet means to said separating means and to.place said pressure responsive means in and out of operative relation.

i V11. In an ice eliminating system for aircraft of the class includinga plurality of inflatable boots formed of a rubber-like material andmounted on airfoil surfaces of said aircraft, a pump for providing asource of superatmospheric air pressure, air distributor Valves forcontrolling the inflation and deflation of said boots, air conduit meansfor conducting the superatmospheric air pressure from said pump to saiddistributor valves for inilating said boots, electrical circuit meansincluding a manually operable switch means for controlling the operationof said air distributor valvesand means for removing oil from the oilladened air from said pump; the improvement comprising an air dischargeconduit leading to atmosphere, means for connecting said dischargeconduit to the air inlet side of said oil removing means, valve meansfor regulating said connecting means to said disl charge conduit andthereby the air inlet pressure to said oil removing means duringoperation of said system, and electromagnetic means for controlling theoperation of said valve means, said electromagnetic means connected insaid electrical circuit means and controlled through operation of saidswitch means in such a manner as to cause said valve means to close theconnection of said pump to said oil separator means during inoperationof said System and open said connection at such times as said system isin an operating condition, and differential pressure responsive meansfor operating said valve means when said system is in said operatingcondition so as to maintain the superatmospheric air pressure applied tosaid boots at a pressure in excess of prevailing atmospheric pressure bya predetermined value.

12. An ice eliminating system for aircraft of the class including aplurality of inflatable boots formed of a rubber-like material andmounted on airfoil surfaces of said aircraft, a pump for providing asource of super-atmospheric air pressure for inilating said boots, meansfor removing oil from the air from said pump, said means connectedbetween said pump and said boots, and an air discharge conduit for saidpump leading to the atmosphere; characterized by the fact that there iscombined with said oil removing means a valve means for alternatelyconnecting the superatmospheric air pressure from said pump to saiddischarge conduit or to said iniiatable boots through said oil removingmeans, and diierential pressure responsive means effective under saidlast mentioned condition for operating said valve means so as toregulate said discharge conduit to maintain the superatmospheric airpressure to said boots at a pressure in excess of prevailing atmosphericpressure by 'a predetermined value.

13. A device of the character described comprising, in combination, acasing having inlet and outlet means for air under superatmosphericpressure, means vcarried by said casing for removing oil from said airand operatively connected between said inlet and outlet means, means forregulating said air inlet means, differential pressure responsive meanssensitive to prevailing atmospheric pressure and the superatmosphericpressure, and means operatively connecting said differential pressureresponsive means to said regulating means to adjust said regulatingmeans -in accordance with the differential between said prevailingpressures so as to maintain the pressure of the air at said outlet meansat a pressure in excess of the prevailing atmospheric pressure by apredetermined value.

14. A device of the character described `comprising, in combination, acasing having inlet and outlet means for air under superatmosphericpressure, means carried by said casing for separating oil from said airand operatively connected between said inlet and outlet means, valvemeans carried by said casing for regulating the air inlet means, motormeans to position said valve means, control means for said motor means,differential pressure responsive means sensitive to prevailingatmospheric pressure and the superatmospheric pressure, and meansoperatively connecting said diierential pressure responsive means tosaid control means to cause said motor means to position said valvemeans so as to maintain the pressure of the air at said outlet means ata pressure in excess of the prevailing atmospheric pressure by apredetermined value.

DONALD M. LAWRENCE.

Referente-s caes in the sie of this patent UNITED srAfr-Es PATENTsNumber Name Date 246,348 Sloane Aug. 30, 1881 1,231,293 Peters June 26,1917 1,237,922 Lucus Aug. 21, 1917 1,288,578 Hateld Dec. 24, 19181,889,120 Donovan Nov. 29, 1932 2,379,181 Pontius June 26, 19452,405,362 Lehman et al. Aug. 6, 1946 2,476,198 Lawrence July 12, 1949

